Happiness， like unhappiness， is a proactive choice.
幸福，就像不幸一样，是一个主动的选择。
"No man really knows about other human beings. The best he can do is to suppose that they are like himself."
历史不是机械的，因为人们有自由去改变它。
The mathematician's best work is art, a high perfect art, as daring as the most secret dreams of imagination, clear and limpid.
我知道无论我变得多么优秀，我总能进步。